Image courtesy of Findings
It may not be quite old enough to earn the distinction of being the world's oldest living organism - that "honor" goes to the bristlecone pine tree (aged 5,000 years) - but, at 4,000 years of age, Leiopathes glaberrima, a deep-water coral species, does set the record for being the oldest animal living under the sea.
Located on the floor of the Pacific Ocean, off Hawaii, the 3 meters tall, (extremely) long-lived "black coral" could yield some valuable clues about past incidents of climate change; specifically, it could better scientists' understanding of how oceans draw down carbon dioxide - and of ocean acidification in general. Brendan Roark of Texas A&M; University, who led a research expedition in 2006 to study the corals' climate records, presented his findings at the recent AAAS meeting. How long they can live is anybody's guess, Roark told Science's Erik Stokstad. He and his colleagues used radiocarbon dating to determine the coral's age. What this suggests, he said, is that the harvesting of deep-water coral for jewelry should be outright banned; because the corals grow at such an anemic rate, any level of harvesting would likely wipe out the remaining specimens - those not yet affected by ocean acidification.
Roark believes it could be possible to reconstruct records of subsurface temperature variability and ocean circulation changes, which would provide some insight on climate change incidents and help predict future effects. By comparison, that ocean quahog clam we mentioned a while back - aged 405 years - seems almost sprightly.